The following figure shows a more recent satellite data
trend from the RSS analysis 1979 - 2008 [http://www.ssmi.com/msu/msu_data_description.html].
The left-hand figure shows regional warming around the world, the right-hand
figure shows the average warming by latitude – zero warming at 60 degrees S
with increasing warming into the Arctic. This illustrates that recent
warming is a northern hemisphere phenomenon.

The
following figure shows the temperature change from 1979 – 2009 from the GISS
temperature data (including all the adjustments) [http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2010&month_last=2&sat=4&sst=1&type=trends&mean_gen=0112

&year1=1979&year2=2009&base1=1951&base2=1980&radius=1200&pol=reg]

The graph
of “Zonal Mean” above, shows the variation by latitude showing that it is a northern
hemisphere and mainly Arctic phenomenon.

IPCC AR4 Report

The
following figure is from the IPCC Fourth Assessment Report (AR4) Figure 9.6
(2007). It shows the change in temperature (C per decade) by latitude. The
black line shows the observed temperature, the blue band shows the output of
the computer models including only natural factors, whereas the pink band
shows the output of computer models including anthropogenic CO2. Notice that the
models without CO2 (blue shaded area) can explain all of the warming for most
of the world up to 30 degrees north latitude. This figure also shows
cooling in Antarctica with warming increasing in the Arctic.

Hadley Center Data

The
following figures show the average temperature anomalies for the northern
(left) and southern (right) hemispheres from the UK Met Office Hadley Center
HadCRUT3 data used by the IPCC (note that the temperature y-axis scales are
different). [http://hadobs.metoffice.com/hadcrut3/diagnostics/index.html]

The
following figure compares the northern (red)
and southern (green) hemispheres
from the above figures put to a common scale.

The
following figure shows a close up of the above figure for temperatures since
1970 (1970 was chosen since the IPCC states that the warming prior to then
was from natural causes). Both hemispheres have exhibited slight cooling for the
last decade although the cooling trend is more distinct for the southern
hemisphere, which never had as much warming. Since 1970 when the IPCC
attributes the start of warming due to CO2, the northern hemisphere has
warmed about 0.5 degrees C, while the southern hemisphere has warmed only
half as much.

An Arctic Phenomenon

The
following figure compares the Arctic temperature trends with global
temperature trends. [http://research.iarc.uaf.edu/multidecadal_variability/ocean.php]
Two observations are evident from this graph: the recent Arctic warming is
not unprecedented, and the Arctic warming is much greater than the global
warming.

Comparison of
Northern Hemisphere / Southern Hemisphere / Tropics

The
following figure shows the global average lower troposphere temperature (near
the Earth’s surface) from satellite data, for the northern hemisphere (north
of 20N), the tropics (20N – 20S) and the southern hemisphere (south of 20S)
(figure from http://climate4you.com/).
[Satellite data is more reliable than averages of surface stations, but is
only available since 1979 - which covers most of the period that the IPCC
says exhibits warming due to CO2.]

The
following figure combines the above three graphs, showing the northern hemisphere, tropics and southern
hemisphere. The northern hemisphere has warmed about 0.5 degrees
C, while the southern hemisphere has warmed about 0.1 C and the tropics show
no net warming over the 30 years of available satellite data.

Comparison of Arctic
/ Antarctic

The
following figure shows the global average lower troposphere temperature (near
the Earth’s surface) from satellite data, for the northern and southern polar
regions (figure from http://climate4you.com/).

The
following figure combines the above two graphs, showing the northern polar (Arctic) and southern polar (Antarctic) regions. The
northern polar region has warmed about 1.0 degrees C, while the southern
polar region has not warmed at all over the 30 years of available satellite
data.

The ice
extent in the Polar Regions has been measured since 1979 – the start of the
satellite era for earth measurements. The following figures show sea ice
extent anomalies for the Arctic (left) and Antarctic (right) to March 2009 [http://arctic.atmos.uiuc.edu/cryosphere/]

The
following figure overlays the Antarctic ice anomalies (green) from above, on
the Arctic ice anomalies (black) from above. A polar divergence began around
1998 (when the major El Nino of 1997-98 occurred). The divergence is due to
divergence in sea surface temperature trends as shown in the next section.

As shown
in the following figure, most of the world had normal (white, light yellow)
or below normal (blue shades) temperatures. The global average is affected by
one small area of the Arctic having much higher than normal temperatures.

Conclusion

Conclusion:
The empirical data show that warming in recent decades is a northern
hemisphere phenomenon – in particular an Arctic phenomenon –with no
significant warming in the tropics or southern hemisphere.

It is not
a global phenomenon.

Medieval Warm Period

The IPCC /
CRU has gone to considerable effort to eradicate the Medieval Warm Period
(MWP), as well as to deny that it was global. CRU’s Phil Jones stated: “if the MWP was shown to be
global in extent and as warm or warmer than today … then obviously the late
20th century warmth would not be unprecedented.” This is a red herring
since the late 20th century is also clearly not global.